In U.S. Pat. No. 3,650,766, there is disclosed a process for the manufacture of fabricated food products. In one embodiment disclosed in U.S. Pat. No. 3,650,766, a slurry of food product is extruded or otherwise molded into a desired shape and its outer surface is sprayed or otherwise washed with a solution containing a gel-forming material. The formed food product coated with the gel-forming material is then contacted with a source of alkaline earth ions, for example, by contact with a spray or bath containing such ions, and the resultant gel formation helps to maintain the shape of the fabricated food product.
In another technique disclosed in the No. '766 patent (see, for example, EXAMPLE 1), the food product (and other minor ingredients such as wheat, flour, salt and sugar) is mixed in batches with the gel-forming material to form a slurry which is fed through appropriate extrusion apparatus. The extruded product is then contacted with a gelling agent, and the resultant gel helps to maintain the shape of the extruded food product.
One of the advantages alleged to flow from the above-described batch processing technique is the claim that the process is time indpendent. That is to say, one of the claimed advantages of this type of process is that the food products and the gelling material can allegedly be premixed, stored "on the shelf" and utilized whenever it is desired to produce the fabricated food product. This is to be contrasted with a batch process wherein quantities of the food products are mixed with the gelling material and the gelation agent such that gelation begins to occur immediately (even if a sequestering system is included) making subsequent extrusion that much more difficult. Unfortunately, and as will be discussed below, even the first process is not in reality time independent since workers must take into account the deteriorating effect of time on gel strength.
It has been suggested in the prior art that one way to produce fabricated food products in a fashion which would eliminate these problems is to produce the fabricated food product on a continuous basis. That is, feed the extruder with a mixture of the food products and the gel-forming material (with or without the gelation agent) on a continuous basis immediately preceding the extrusion step. Such a process is broadly suggested in the Rivoche U.S. Pat. No. 2,791,508, although no specific mechanism is shown in Rivoche or know, up to the time of the present invention, which will effectively perform such functions.